John was a weaver when he married Mary Mather at Bolton and a Weaver in 1840 when Martha married.
Alice (1818-1819) is the only child (death) record of parents John and Mary Allen following their marriage. It shows John a Tapemaker at Collyhurst, so this is probably another family.
There are Martha and David Allen, children of John a weaver and Mary of Hopwood baptised at Prestwich in 1817 and 1820 but this family also had Richard of Prestwich in May 1815 (before the 1816 marriage) so this may also be another family, or possibly Richard was illegitimate or from another family. There are no Prestwich baptisms before Richard. After that they had Walker and Arthur baptised at Middleton, all recorded as abode Hopwood.
In 1841, John a cotton weaver and Mary (both 50) were at Back York Street, Heywood, Bury with David (20) and Arthur (15).
David's Crensus records show he was born in Birch, Middleton.
In 1851, John (63, Wid) was living at Birtle with his son Arthur (25). This John died in Birtle in 1851, aged 63.
In 1861, There is John and Mary Allen (72 & 71) at Eten Hill (Beer House), Radcliffe with son James (31). Therefore there are two possible families. This John died at Radcliffe in 1874, aged 86 (and Mary in 1872, aged 84).
In 1871, John Allen (84, Wid) was living with his son David Allen, wife Ann (both 50) and family at Newton.